CN111512469A

CN111512469A - Lead-acid battery

Info

Publication number: CN111512469A
Application number: CN201880083409.0A
Authority: CN
Inventors: 秋本尚
Original assignee: GS Yuasa International Ltd
Current assignee: GS Yuasa International Ltd
Priority date: 2017-12-25
Filing date: 2018-12-17
Publication date: 2020-08-07
Also published as: JP6973039B2; AU2018396232A1; US11424507B2; EP3706196A1; US20210175575A1; JP2019114434A; WO2019131260A1; EP3706196A4

Abstract

A lead-acid battery (100) is provided with a lid (14). A communication chamber (520) is formed inside the cover (14). In the communication chamber (520), a first distance between the inner wall (432) and the vent hole (321) in the side walls (506, 522) is shorter than a second distance between the inner wall (432) and the communication holes (328, 330), and the distal end portion (432A) of the inner wall (432) on the other side in the first direction is formed on the other side in the first direction than the vent hole (321).

Description

Lead-acid battery

Technical Field

The technology disclosed in this specification relates to lead storage batteries.

Background

The lead-acid battery is mounted on a vehicle such as an automobile, and is used as a power source of the vehicle and a power supply source for supplying electric power to electric components mounted on the vehicle. Such a lead-acid battery includes: an electrolytic cell having an opening and formed therein with a plurality of cell compartments arranged in a predetermined direction; a lid joined to an opening of the electrolytic cell; and an electrode plate group disposed in each of the cell compartments.

In the lead-acid battery, for example, gas (oxygen gas, hydrogen gas) is generated from an electrode plate in the electrolytic cell during charging, and the internal pressure of the cell chamber rises, which may cause deformation of the electrolytic cell. Therefore, a lead-acid battery having a gas discharge structure for discharging gas generated in an electrolytic cell to the outside of the lead-acid battery is known. Specifically, the lid includes a lower structure joined to the opening of the electrolytic cell and an upper structure disposed above the lower structure, and a chamber and a passage are formed between the lower structure and the upper structure. The chamber is formed with an opening for exhaust communicating with the cell chamber of the electrolytic cell, and is formed with a chamber outlet communicating with the passage. The passageway extends from the chamber outlet to a discharge port formed in an outer surface of the cover. The gas generated in the cell chamber is discharged to the outside of the lead acid battery through the opening for exhaust, the chamber, the passage, and the discharge port (see, for example, patent document 1 below).

Patent document 1: japanese laid-open patent publication No. 57-143261

However, the lead-acid battery may have an inverted posture in which the lid and the electrolytic cell are turned upside down due to, for example, the fall during transportation. In the conventional lead-acid battery including the lid having the above-described gas discharge structure, when the lead-acid battery is in an inverted posture, there is a concern that: the electrolyte in the cell chamber flows into the communication chamber (chamber) and flows out from the communication chamber to the passage. If the electrolyte flows out of the communication chamber, the electrolyte is likely to leak out of the lead storage battery.

Disclosure of Invention

In the present specification, the following techniques are disclosed: the electrolyte can be prevented from flowing out of the communication chamber when the lead-acid battery is in an inverted posture.

The lead-acid battery disclosed in the present specification includes: an electrolytic cell having an opening on one side in a first direction and having a housing chamber formed therein, the housing chamber communicating with the opening; a positive electrode and a negative electrode accommodated in the accommodation chamber of the electrolytic cell; and a cover configured to close the opening of the electrolytic cell, the cover having a discharge port formed on an outer surface thereof, a communication chamber is formed in the lid, the communication chamber being surrounded by a partition wall between the communication chamber and the storage chamber, an opposing wall opposing the partition wall in the first direction, and a side wall connecting the partition wall and the opposing wall, a communication hole communicating with the storage chamber is formed in the partition wall, a vent hole communicating with the discharge port of the lid is formed in the side wall, the communication chamber includes an inner wall disposed to face the vent hole, a first distance between the inner wall and the vent hole in the side wall is shorter than a second distance between the inner wall and the communication hole, the inner wall has a distal end portion on the other side in the first direction formed at a position closer to the other side in the first direction than the vent hole.

Drawings

Fig. 1 is a perspective view showing an external configuration of a lead-acid battery 100 according to the present embodiment.

Fig. 2 is an explanatory view showing a YZ cross-sectional structure of the lead acid battery 100 at a position II-II in fig. 1.

Fig. 3 is an explanatory view showing a YZ cross-sectional structure of the lead acid battery 100 at the position III-III in fig. 1.

Fig. 4 is an explanatory diagram showing the XY plane structure of the cap 300 as viewed from the upper side (the upper cap 400 side).

Fig. 5 is an XY plane configuration diagram of the upper cover 400 as viewed from the lower side (the middle cover 300).

Fig. 6 is a perspective view showing the correspondence relationship between the internal structures of the middle cap 300 and the upper cap 400.

Fig. 7 is an explanatory diagram showing the XZ sectional structure of the cap 14 at the position VII-VII in fig. 6.

Fig. 8 is an XY plan view showing the structure of the upper surface side of the middle cap 300.

Fig. 9 is a perspective view showing the structure of the lower surface side of the upper cover 400.

Fig. 10 is an explanatory diagram showing a change in the water level of the electrolyte 18 in the cell communication unit 520 when the lead storage battery 100 is in the inverted posture.

Detailed Description

The technique disclosed in the present specification can be implemented as follows.

(1) The lead-acid battery disclosed in the present specification includes: an electrolytic cell having an opening on one side in a first direction and having a housing chamber formed therein, the housing chamber communicating with the opening; a positive electrode and a negative electrode accommodated in the accommodation chamber of the electrolytic cell; and a cover configured to close the opening of the electrolytic cell, the cover having a discharge port formed on an outer surface thereof, a communication chamber is formed inside the lid, the communication chamber being surrounded by a partition wall between the communication chamber and the storage chamber, an opposing wall opposing the partition wall in the first direction, and a side wall connecting the partition wall and the opposing wall, a communication hole communicating with the storage chamber is formed in the partition wall, a vent hole communicating with the discharge port of the lid is formed in the side wall, the communication chamber includes an inner wall disposed to face the vent hole, a first distance between the inner wall and the vent hole in the side wall is shorter than a second distance between the inner wall and the communication hole, the terminal portion of the inner wall on the other side in the first direction is formed on the other side in the first direction with respect to the vent hole. When the lead-acid battery is in the inverted posture, the electrolyte in the electrolytic cell flows into the communication chamber through the communication hole formed in the partition wall of the communication chamber, and the water level of the electrolyte in the communication chamber rises. Moreover, there is a concern that: when the water level of the electrolyte reaches the vent hole formed in the side wall of the communication chamber, the electrolyte flows out of the communication chamber through the vent hole. Here, if a configuration is assumed in which the distal end portion of the inner wall is disposed on one side (the side opposite to the electrolytic cell) in the first direction with respect to at least a part of the vent hole, or a configuration is assumed in which the distance between the inner wall and the vent hole is longer than the distance between the inner wall and the communication hole, the electrolyte solution easily flows out of the communication chamber. That is, in these structures, there is no obstacle that prevents air outside the communication chamber from flowing into the communication chamber through the vent hole. Therefore, air outside the communication chamber easily enters the communication chamber through the vent hole. As a result, the electrolyte easily flows out of the communication chamber due to gas-liquid replacement inside and outside the communication chamber. In contrast, in the lead-acid battery of the present invention, the communication chamber includes an inner wall disposed so as to face the vent hole at a position close to the vent hole, and a distal end portion of the inner wall on the other side (the electrolytic cell side) in the first direction is formed at a position closer to the other side in the first direction than the vent hole. Therefore, air outside the communication chamber is less likely to enter the communication chamber through the vent hole, and gas-liquid replacement inside and outside the communication chamber can be suppressed. This can prevent the electrolyte from flowing out of the communication chamber when the lead-acid battery is in the inverted posture.

(2) In the lead-acid battery, the inner wall may be a cylindrical exhaust tube wall protruding from the opposing wall toward the communication hole. When the lead-acid battery is in an inverted posture, the electrolyte in the electrolytic cell flows into the exhaust pipe wall disposed in the communication chamber through the communication hole. Then, when the exhaust cylinder wall is filled with the electrolyte, the electrolyte in the exhaust cylinder wall overflows to the opposite wall of the communication chamber. Then, in the communication chamber, when the level of the electrolyte outside the exhaust cylindrical wall becomes equal to the level of the electrolyte inside the exhaust cylindrical wall, the rate of increase in the level of the electrolyte inside the communication chamber is slowed. Here, assuming that the distal end portion of the exhaust cylinder wall is formed at a position on one side (the side opposite to the electrolytic cell) in the first direction with respect to at least a part of the vent hole, a large amount of the electrolytic solution flows out of the communication chamber. That is, in such a configuration, during a low water level speed period in which the rising speed of the water level of the electrolyte is slow, a continuous space continuously connecting from the vent hole to the communication hole exists in the communication chamber, and gas-liquid replacement inside and outside the communication chamber is promoted via the continuous space, so that a large amount of the electrolyte flows out of the communication chamber. In contrast, in the lead-acid battery of the present invention, the end portion of the exhaust tube wall is formed on the other side (the electrolytic cell side) in the first direction than the vent hole. Therefore, when the water levels of the electrolyte inside and outside the exhaust funnel wall become equal, the vent hole is already closed by the electrolyte, and the air outside the communication chamber is less likely to enter the communication chamber through the vent hole. This makes it difficult for gas-liquid replacement to occur inside and outside the communication chamber during the low water level speed period, and thus the outflow of the electrolyte to the outside of the communication chamber can be suppressed. That is, according to the lead-acid battery of the present invention, the outflow of the electrolyte to the outside of the communication chamber can be more effectively suppressed when the lead-acid battery is in the inverted posture.

(3) In the lead-acid battery, the communication hole may include an air discharge hole communicating with the housing chamber and a return hole located on the other side in the first direction than the air discharge hole and communicating with the housing chamber, and the air vent may be formed in the communication chamber at a position closer to the air discharge hole than the return hole. In the structure in which the vent hole and the return hole positioned on the other side (the side of the electrolytic cell) in the first direction from the vent hole are formed in the communication chamber, when the lead-acid battery is in the inverted posture, the water level of the electrolyte in the communication chamber reaches the vent hole before the return hole. As a result, the vent hole is closed by the electrolyte solution, and the return hole is opened. Here, if the vent hole is formed closer to the return hole than the exhaust hole, a large amount of the electrolyte flows out of the communication chamber. That is, even if the water level of the electrolyte in the communication chamber reaches the air outlet hole, a continuous space continuously connecting from the air vent hole to the return hole exists in the communication chamber, so that gas-liquid replacement inside and outside the communication chamber is promoted via the continuous space, and a large amount of the electrolyte flows out of the communication chamber. In contrast, in the lead-acid battery, the vent hole is formed closer to the air vent hole than the return hole. Therefore, when the lead-acid battery is in an inverted posture and the water level of the electrolyte in the communication chamber reaches the air outlet hole, the electrolyte accumulated in the communication chamber is present between the vent hole and the return hole in the communication chamber. That is, a continuous space continuously connecting from the vent hole to the return hole is not formed in the communication chamber. Therefore, gas-liquid replacement inside and outside the communication chamber can be suppressed. Thus, according to the lead-acid battery of the present invention, the outflow of the electrolyte to the outside of the communication chamber can be more effectively suppressed when the lead-acid battery is in the inverted posture.

A. The implementation mode is as follows:

a-1. Structure:

(Structure of lead storage battery 100)

Fig. 1 is a perspective view showing an external configuration of a lead-acid battery 100 according to the present embodiment, fig. 2 is an explanatory view showing a YZ cross-sectional configuration of the lead-acid battery 100 at a position II-II in fig. 1, and fig. 3 is an explanatory view showing a YZ cross-sectional configuration of the lead-acid battery 100 at a position III-III in fig. 1. Note that, in fig. 2 and 3, for convenience, the structure of the electrode group 20 described later is shown for easy understanding, and this structure is expressed differently from the actual structure. The figures show mutually orthogonal XYZ axes for determining the direction. In the present specification, the positive Z-axis direction is referred to as the "upward direction" and the negative Z-axis direction is referred to as the "downward direction" for convenience, but the lead-acid battery 100 may actually be provided in an orientation different from that described above. The vertical direction (Z-axis direction) corresponds to a first direction of claims, the vertical direction (Z-axis positive direction) corresponds to one side of the first direction of claims, and the vertical direction (Z-axis negative direction) corresponds to the other side of the first direction of claims.

The lead storage battery 100 can emit a large current in a short time and can exhibit stable performance in various environments, and therefore is mounted in a vehicle such as an automobile, for example, and used as a power supply source to a starter at the time of starting an engine and a power supply source to various electrical components such as a lamp. As shown in fig. 1 to 3, the lead acid battery 100 includes a case 10, a positive electrode-side terminal portion 30, a negative electrode-side terminal portion 40, and a plurality of electrode plate groups 20. Hereinafter, the positive-electrode-side terminal portion 30 and the negative-electrode-side terminal portion 40 are collectively referred to as "

terminal portions

30 and 40".

(Structure of case 10)

The housing 10 has an electrolytic cell 12 and a lid 14. The electrolytic cell 12 is a substantially rectangular parallelepiped container having an opening on the upper surface, and is formed of, for example, a synthetic resin. The lid 14 is a member arranged to close the opening of the electrolytic cell 12, and is formed of, for example, a synthetic resin. The peripheral portion of the lower surface of the lid 14 and the peripheral portion of the opening of the electrolytic bath 12 are joined by, for example, thermal welding, thereby forming a space that is airtight to the outside within the case 10. The space in the case 10 is divided by partition walls 58 into a plurality of (for example, 6) cell compartments (housing chambers) 16 arranged in a predetermined direction (in the X-axis direction in the present embodiment). Hereinafter, the direction in which the plurality of cell compartments 16 are arranged (X-axis direction) is referred to as "cell arrangement direction". As shown in fig. 1 and the like, the posture of the lead acid battery 100 when the lid 14 is disposed above the electrolytic bath 12 is referred to as a "normal posture", and the posture of the lead acid battery 100 when the lid 14 is disposed below the electrolytic bath 12 (the posture after turning the lead acid battery 100 upside down shown in fig. 1 and the like) is referred to as an "inverted posture". In the following description, unless otherwise specified, it is assumed that the lead storage battery 100 is in a normal posture. The detailed structure of the cover 14 will be described later.

One plate group 20 is accommodated in each cell compartment 16 in the housing 10. Therefore, for example, when the space in the case 10 is divided into 6 cell compartments 16, the lead acid battery 100 includes 6 electrode plate groups 20. In addition, an electrolyte 18 containing dilute sulfuric acid is contained in each cell chamber 16 in the case 10, and the entire electrode group 20 is immersed in the electrolyte 18. The electrolyte 18 is injected into the cell chamber 16 through an injection hole 311 provided in the lid 14, which will be described later.

(Structure of electrode plate group 20)

The electrode group 20 includes a plurality of positive electrode plates 210, a plurality of negative electrode plates 220, and separators 230. The plurality of positive electrode plates 210 and the plurality of negative electrode plates 220 are arranged such that the positive electrode plates 210 and the negative electrode plates 220 are alternately arranged. Hereinafter, the positive electrode plate 210 and the negative electrode plate 220 are also collectively referred to as "

electrode plates

210 and 220".

The positive electrode plate 210 includes a positive electrode current collector 212 and a positive electrode active material 216 supported by the positive electrode current collector 212. The positive electrode current collector 212 is a conductive member having a skeleton arranged in a substantially grid-like or mesh-like shape, and is formed of, for example, lead or a lead alloy. The positive electrode current collector 212 has a positive electrode lug 214 projecting upward near the upper end thereof. The positive electrode active material 216 contains lead dioxide. The positive electrode active material 216 may further contain known additives.

The negative electrode plate 220 includes a negative electrode current collector 222 and a negative electrode active material 226 supported by the negative electrode current collector 222. The negative electrode current collector 222 is a conductive member having a skeleton arranged in a substantially grid-like or mesh-like shape, and is formed of, for example, lead or a lead alloy. The negative electrode current collector 222 has a negative electrode ear 224 protruding upward near the upper end thereof. The negative electrode active material 226 contains lead. The negative electrode active material 226 may further contain known additives.

The separator 230 is made of an insulating material (e.g., glass or synthetic resin). The separator 230 is disposed between the adjacent positive and

negative electrode plates

210 and 220. The separator 230 may be an integral member or may be a collection of a plurality of members provided for each combination of the positive electrode plate 210 and the negative electrode plate 220.

The positive electrode tab portions 214 of the plurality of positive electrode plates 210 constituting the electrode plate group 20 are connected to the positive electrode-side bus bar 52 made of lead or a lead alloy, for example. That is, the plurality of positive electrode plates 210 are electrically connected in parallel via the positive electrode-side bus bar 52. Similarly, the negative electrode lug portions 224 of the plurality of negative electrode plates 220 constituting the electrode plate group 20 are connected to the negative-side bus bar 54 made of, for example, lead or a lead alloy. That is, the plurality of negative electrode plates 220 are electrically connected in parallel via the negative electrode side bus bar 54. Hereinafter, the positive-side bus bar 52 and the negative-side bus bar 54 are also collectively referred to as "bus bars 52, 54".

In the lead-acid battery 100, the negative-side bus bar 54 accommodated in one cell compartment 16 is connected to the positive-side bus bar 52 accommodated in another cell compartment 16 adjacent to one side (for example, the X-axis positive direction side) of the one cell compartment 16 via a connecting member 56 made of, for example, lead or a lead alloy. The positive-side bus bar 52 housed in the one cell compartment 16 is connected to a negative-side bus bar 54 housed in another cell compartment 16 adjacent to the other side (for example, the X-axis negative direction side) of the one cell compartment 16 via a connection member 56. That is, the plurality of electrode plate groups 20 included in the lead storage battery 100 are electrically connected in series via the bus bars 52 and 54 and the connecting member 56. As shown in fig. 2, the positive-side bus bar 52 housed in the cell compartment 16 located at one end portion in the cell arrangement direction (the X-axis negative direction side) is connected to a positive post 34 described later, instead of the connection member 56. As shown in fig. 3, the negative-side bus bar 54 housed in the cell compartment 16 located at the end on the other side (the positive X-axis direction side) in the cell arrangement direction is connected to the negative post 44 described later, instead of the connection member 56.

(Structure of terminal portions 30 and 40)

The positive terminal portion 30 is disposed in the vicinity of one end (X-axis negative direction side) of the cell arrangement direction of the case 10, and the negative terminal portion 40 is disposed in the vicinity of the other end (X-axis positive direction side) of the cell arrangement direction of the case 10.

As shown in fig. 2, the positive-side terminal portion 30 includes a positive-side post sleeve 32 and a positive post 34. The positive electrode side post sleeve 32 is a substantially cylindrical conductive member formed with a hole penetrating in the vertical direction, and is formed of, for example, a lead alloy. The lower portion of the positive electrode side post 32 is embedded in the lid 14 by insert molding, and the upper portion of the positive electrode side post 32 protrudes upward from the upper surface of the lid 14. The positive post 34 is a substantially cylindrical conductive member, and is formed of, for example, a lead alloy. The positive post 34 is inserted into the hole of the positive side post sleeve 32. The upper end of the positive electrode post 34 is located at substantially the same position as the upper end of the positive electrode side post sleeve 32, and is joined to the positive electrode side post sleeve 32 by welding, for example. The lower end of the positive post 34 protrudes downward from the lower end of the positive post sleeve 32, and further protrudes downward from the lower surface of the lid 14, and is connected to the positive bus bar 52 housed in the cell chamber 16 located at one end (the X-axis negative direction side) in the cell array direction, as described above.

As shown in fig. 3, the negative-side terminal portion 40 includes a negative-side post sleeve 42 and a negative post 44. The negative electrode side post 42 is a substantially cylindrical conductive member formed with a hole penetrating in the vertical direction, and is formed of, for example, a lead alloy. The lower portion of the negative electrode side post 42 is embedded in the lid 14 by insert molding, and the upper portion of the negative electrode side post 42 protrudes upward from the upper surface of the lid 14. The negative electrode tab 44 is a substantially cylindrical conductive member, and is formed of, for example, a lead alloy. The negative electrode tab 44 is inserted into the hole of the negative electrode tab cover 42. The upper end portion of the negative electrode tab 44 is located at substantially the same position as the upper end portion of the negative electrode side tab 42, and is joined to the negative electrode side tab 42 by welding, for example. The lower end portion of the negative electrode post 44 protrudes downward from the lower end portion of the negative electrode-side post cover 42, and further protrudes downward from the lower surface of the lid 14, and is connected to the negative electrode-side bus bar 54 housed in the cell compartment 16 located at the end portion on the other side (the X-axis positive direction side) in the cell arrangement direction, as described above.

During discharge of the lead acid battery 100, a load (not shown) is connected to the positive electrode side post 32 of the positive electrode side terminal portion 30 and the negative electrode side post 42 of the negative electrode side terminal portion 40, and electric power generated by a reaction in the positive electrode plates 210 (a reaction of generating lead sulfate from lead dioxide) and a reaction in the negative electrode plates 220 (a reaction of generating lead sulfate from lead) of each electrode plate group 20 is supplied to the load. In addition, when the lead storage battery 100 is charged, a power supply (not shown) is connected to the positive-side post 32 of the positive-side terminal portion 30 and the negative-side post 42 of the negative-side terminal portion 40, and the lead storage battery 100 is charged by a reaction in the positive plates 210 (a reaction in which lead dioxide is generated from lead sulfate) and a reaction in the negative plates 220 (a reaction in which lead is generated from lead sulfate) of each of the electrode plate groups 20 by electric power supplied from the power supply.

A-2. detailed structure of the lid 14:

as shown in fig. 2 and 3, the lid 14 is a lid body of a so-called double lid structure, and includes a middle lid 300 and an upper lid 400. An inner space of the cover 14 is formed between the middle cover 300 and the upper cover 400. Fig. 4 is an explanatory diagram showing an XY plane structure of the middle cap 300 as viewed from the upper side (the upper cap 400 side), and fig. 5 is an XY plane structure diagram of the upper cap 400 as viewed from the lower side (the middle cap 300). Fig. 6 is a perspective view showing the internal structure of the middle cap 300 and the upper cap 400. In fig. 6, for convenience, the upper cover 400 is shown separated from the middle cover 300, and only a portion of the middle cover 300 and the upper cover 400 constituting one compartment 500 is shown. Fig. 7 is an explanatory diagram showing the XZ sectional structure of the cap 14 at the position VII-VII in fig. 6. Fig. 7 shows an XZ cross-sectional structure of the lid 14 in a state where the upper lid 400 shown in fig. 6 is disposed on the middle lid 300.

A-2-1. inner space of the cap 14:

the internal space of the cover 14 is divided by partition walls 506 into a plurality of (the same number as the number of the cell compartments 16) divided compartments 500 arranged in the cell arrangement direction. Each of the partition chambers 500 corresponds to one of the plurality of unit cell chambers 16, and is located directly above the corresponding unit cell chamber 16. The following specifically explains the present invention.

Specifically, as shown in fig. 2 to 4 and 6, the intermediate lid 300 includes a flat plate-shaped intermediate lid main body 302, an intermediate lid peripheral wall 304, and a plurality of (one less than the number of the cell compartments 16) intermediate lid partition walls 306. The middle lid peripheral wall 304 is disposed in a region on the opposite side of the

terminal portions

30 and 40 in a direction (hereinafter referred to as "depth direction" in the Y-axis direction) substantially orthogonal to the cell arrangement direction (X-axis direction) on the upper surface of the middle lid main body 302. The middle cap peripheral wall 304 is formed to protrude upward from the upper surface of the middle cap main body 302. The shape of the middle lid peripheral wall 304 as viewed in the vertical direction (as viewed in the Z-axis direction) is a substantially rectangular frame shape. The plurality of intermediate lid partition walls 306 are arranged at predetermined intervals in the intermediate lid peripheral wall 304 in the cell arrangement direction. Each of the intermediate cap partition walls 306 extends in the depth direction, and both ends of each of the intermediate cap partition walls 306 in the depth direction are connected to the inner peripheral surface of the intermediate cap peripheral wall 304 (see fig. 4).

On the other hand, as shown in fig. 2, 3, 5, and 6, the upper cover 400 includes a flat upper cover main body 402, an upper cover peripheral wall 404, and a plurality of upper cover partition walls 406 (one smaller than the number of the cell compartments 16). The upper cover peripheral wall 404 is formed to protrude downward from the lower surface of the upper cover main body 402. The upper cover peripheral wall 404 has a substantially rectangular frame shape extending along the peripheral portion of the upper cover main body 402 as viewed in the vertical direction (as viewed in the Z-axis direction). In the upper cover peripheral wall 404, discharge ports 405 penetrating the upper cover peripheral wall 404 are formed at both end portions facing each other in the cell arrangement direction (X-axis direction). The plurality of upper cap partitions 406 are arranged at predetermined intervals in the cell arrangement direction. Each of the upper-cap partition walls 406 extends in the depth direction (Y-axis direction), and both ends of each of the upper-cap partition walls 406 in the depth direction are connected to the inner peripheral surface of the upper-cap peripheral wall 404 (see fig. 5). A first notch 407 is formed in each upper cap partition 406 opening. Note that no notch is formed in each of the above-described intermediate lid partition walls 306 formed in the intermediate lid 300.

The intermediate lid peripheral wall 304 and the upper lid peripheral wall 404 are joined by thermal welding to form a peripheral wall 504 constituting the outer peripheral surface of the lid 14, whereby the above-described internal space is formed inside the lid 14. Further, each of the intermediate cap partition walls 306 and each of the upper cap partition walls 406 are joined by thermal fusion to constitute partition walls 506, whereby the internal space of the cap 14 is divided into a plurality of divided chambers 500. The plurality of compartment chambers 500 communicate with each other through first slit portions 407 formed in the respective cap partition walls 406.

A-2-2. internal structure of each compartment 500:

each of the divided chambers 500 includes an injection chamber 510, a cell communication single chamber 520, and an exhaust flow path 530. The partitioned chamber 500 located at an end in the cell arrangement direction (X-axis direction) (hereinafter referred to as "end-side partitioned chamber 500") further includes a concentrated exhaust chamber 540 (see fig. 2, 3, and 7).

(injection chamber 510)

As shown in fig. 2 and 3, the electrolyte injection chamber 510 is a space for injecting the electrolyte 18 into each cell chamber 16 of the electrolytic bath 12. Specifically, the injection chamber 510 is a space surrounded by an injection side wall 512 having a substantially cylindrical shape when viewed in the vertical direction (when viewed in the Z-axis direction). As shown in fig. 4 and 6, an intermediate cap liquid injection side wall 312 is formed in the upper surface of the intermediate cap main body 302 within the intermediate cap peripheral wall 304 so as to protrude upward from the intermediate cap main body 302. The intermediate cap liquid injection side wall 312 has a substantially cylindrical shape as viewed in the vertical direction. In addition, a liquid inlet 311 penetrating the middle cap body 302 in the vertical direction is formed in the middle cap liquid inlet side wall 312 on the upper surface of the middle cap body 302. The electrolyte solution 18 can be injected into the cell chamber 16 of the electrolytic cell 12 through the injection hole 311. On the other hand, as shown in fig. 5 and 6, an upper cover liquid injection side wall 412 is formed in the upper cover peripheral wall 404 of the lower surface of the upper cover main body 402 so as to protrude downward from the upper cover main body 402 at a position facing the intermediate cover liquid injection side wall 312. The upper cap liquid injection side wall 412 has a substantially cylindrical shape as viewed in the vertical direction. The filling side wall 512 is formed by joining the intermediate cap filling side wall 312 and the upper cap filling side wall 412 by thermal fusion bonding, and a filling chamber 510 is formed inside the cap 14 (see fig. 2 and 3).

(Single cell connected with single chamber 520)

The cell communication single chamber 520 is a space in which communication holes (an air discharge hole 328 and a return hole 330 described later) are formed and which communicates with the cell chambers 16 through the communication holes. Specifically, the cell communication single chamber 520 is a space surrounded by the partition wall 506 and the exhaust side wall 522, and the cell communication single chamber 520 has a substantially trapezoidal shape as viewed in the vertical direction. As shown in fig. 4 and 6, an intermediate lid exhaust sidewall 322 that forms a partition wall of a substantially trapezoidal shape together with the intermediate lid partition wall 306 is formed in the intermediate lid peripheral wall 304 in the upper surface of the intermediate lid main body 302 so as to protrude upward from the intermediate lid main body 302. On the other hand, as shown in fig. 5 and 6, in the upper lid peripheral wall 404 on the lower surface of the upper lid main body 402, an upper lid exhaust sidewall 422 that forms a substantially trapezoidal partition wall together with the upper lid partition wall 406 is formed so as to protrude downward from the upper lid main body 402 at a position facing the middle lid exhaust sidewall 322. The middle cap exhaust sidewall 322 and the upper cap exhaust sidewall 422 are joined by thermal welding to form an exhaust sidewall 522, thereby forming a cell communication single chamber 520 (see fig. 2, 3, and 7) inside the cap 14. As shown in fig. 6, second notch 321 is formed between middle cap partition 306 and middle cap exhaust sidewall 322, and no notch is formed between upper cap partition 406 and upper cap exhaust sidewall 422. Therefore, the cell communication unit chamber 520 communicates with the exhaust flow path 530 via the second notch 321. The cell communication single chamber 520 corresponds to a communication chamber in claims, the partition wall 506 and the exhaust side wall 522 correspond to side walls in claims, and the second notch 321 corresponds to a vent hole in claims.

In addition, the portion of the middle cap main body 302 that is located inside the middle cap partition wall 306 and the middle cap exhaust sidewall 322 as viewed in the up-down direction includes a first partition wall 324, a second partition wall 326, and a step 325 that connects the first partition wall 324 and the second partition wall 326. The first partition wall 324, the second partition wall 326, and the step 325 are walls that partition the cell compartments 16 and the cell communication cell compartment 520. The first partition wall 324 is disposed closer to the second partition wall 326 than to the second cutout 321. As shown in fig. 7, the first partition wall 324 and the second notch 321 are separated from each other in the vertical direction (Z-axis direction). In other words, the second notch 321 is located above the upper surface of the first partition wall 324. Specifically, a stepped portion 327 extending upward from the first partition wall 324 is formed between the first partition wall 324 and the second notch portion 321, and thus the first partition wall 324 and the second notch portion 321 are separated from each other in the vertical direction. The second notch 321 and the lower surface of the upper cover main body 402 are also separated from each other in the vertical direction. In other words, second notch 321 is located below the lower surface of upper cover main body 402.

Further, the first partition wall 324 is formed with an air discharge hole 328 penetrating the first partition wall 324 in the vertical direction. Further, a substantially cylindrical communication cylinder portion 332 surrounding the exhaust hole 328 and extending upward from the first partition wall 324 is formed on the upper surface of the first partition wall 324. The upper end 332A of the communication tube portion 332 is located above the upper surface of the middle cap partition 306 and the upper surface of the middle cap exhaust sidewall 322 and reaches the inside of the upper cap 400 (see fig. 7).

As described above, the second partition wall 326 is disposed at a position distant from the first partition wall 324 with respect to the second notch 321. The second partition wall 326 is located below the first partition wall 324 (on the electrode group 20 side) via a step 325 extending in the vertical direction. The second partition wall 326 is formed with a return hole 330 that penetrates the second partition wall 326 in the vertical direction. That is, the return hole 330 is disposed closer to the liquid surface of the electrolyte 18 than the exhaust hole 328. The first partition wall 324 is inclined obliquely downward toward the second partition wall 326, and the second partition wall 326 is inclined toward the return hole 330 (see fig. 7). Thus, when the lead-acid battery 100 is placed in the normal posture, the electrolyte 18 remaining in the cell communication cell 520 can be smoothly guided to the return hole 330 along the inclination of the first partition wall 324 and the second partition wall 326, and can be returned to the cell chamber 16. The discharge hole 328 and the return hole 330 correspond to communication holes in claims. In addition, the portions of the upper cover main body 402 facing the first partition wall 324 and the second partition wall 326 correspond to facing walls in the claims.

As shown in fig. 6 and 7, an exhaust cylinder wall 432 is formed on the lower surface of the upper lid main body 402 so as to protrude downward from the upper lid main body 402 at a position facing the exhaust hole 328 formed in the first partition wall 324 of the middle lid main body 302. The exhaust cylinder wall 432 has a substantially square tube shape when viewed in the vertical direction (when viewed in the Z-axis direction). The lower end portion 432A of the exhaust cylinder wall 432 is located below the second notch 321. Further, the distal end portion 432A of the exhaust cylinder wall 432 is positioned below the upper end 332A of the communication cylinder portion 332 of the middle cap 300, and the exhaust cylinder wall 432 is disposed so as to surround the communication cylinder portion 332 of the middle cap 300. The exhaust pipe wall 432 corresponds to an inner wall in claims, and a distal end portion 432A of the exhaust pipe wall 432 corresponds to a distal end portion on the other side of the first direction of the inner wall in claims.

Fig. 8 is an XY plan view showing the structure of the upper surface side of the middle cap 300, and the exhaust cylinder wall 432 formed in the upper cap 400 is shown by a two-dot chain line in fig. 8, a part of the exhaust cylinder wall 432 faces the second notch portion 321 (vent hole) formed in the cell communication single chamber 520, and as shown in fig. 8, a first distance L1, which is the shortest distance between the exhaust cylinder wall 432 and the hole forming portion (the notch portion between the upper cap partition wall 406 and the upper cap exhaust side wall 422) in which the second notch portion 321 is formed, is shorter (see fig. 7) than a second distance L2, which is the shortest distance between the exhaust cylinder wall 432 and the portion (the communication cylinder portion 332) in which the exhaust hole 328 is formed (see fig. 2), and the first distance L1 is preferably 3mm or less, and more preferably 2mm or less, in this embodiment, the first distance L1 is 1.5mm, and the end portion 432A of the exhaust cylinder wall 432 is preferably located on the lower side of the entire second notch portion 321 (the cell chamber 16 side), and at least one of the second notch portion is preferably 3mm in the transverse direction, and the width of the second notch portion 321 is preferably 3mm or less, and the width of the second notch portion 321 is preferably 3 mm.

Fig. 9 is a perspective view showing the structure of the lower surface side of the upper cover 400. As shown in fig. 6 and 9, an internal flow path Q that communicates with the second notch 321 and is positioned closer to the cell chamber 16 than the second notch 321 is formed between the exhaust cylinder wall 432 and the exhaust sidewall 522 (the upper lid partition wall 406, the upper lid exhaust sidewall 422). The facing surfaces of the exhaust cylinder wall 432 and the exhaust side wall 522 that face each other to form the internal flow path Q are preferably spaced apart by 3mm or less, more preferably 2mm or less. In the present embodiment, the facing distance is 1.5 mm.

As shown in fig. 6 and 9, at least a part of the surface of the opposed surfaces of the exhaust funnel wall 432 and the exhaust sidewall 522 has a concave-convex portion T. Specifically, of the 4 outer surfaces of the exhaust cylinder wall 432, the outer surface on the return hole 330 side is a substantially flat surface, and a plurality of concave and convex portions T are formed on the remaining 3 outer surfaces. Further, a plurality of concave and convex portions T are formed in portions of the inner peripheral surfaces of the middle lid partition wall 306 and the middle lid exhaust side wall 322 constituting the exhaust side wall 522, which face the remaining 3 outer side surfaces of the exhaust cylinder wall 432. The remaining 3 outer surfaces of the exhaust cylinder wall 432 face the exhaust side wall 522 (the middle lid partition wall 306, the middle lid exhaust side wall 322) at substantially the same distance as the lateral width of the second notch 321, thereby constituting the internal flow path Q. More specifically, on the facing surfaces of the exhaust cylinder wall 432 and the exhaust side wall 522, a plurality of concave and convex portions T extending in the vertical direction (Z-axis direction) are arranged parallel to the facing surfaces and in a direction substantially orthogonal to the vertical direction. The difference in level between the peaks and valleys of the uneven portion T is preferably 0.1mm or more. The concave-convex portion T is not formed on the surface of the partition wall (the first partition wall 324, the second partition wall 326) on the upper cover 400 side where the second notch 321 is formed, and is a substantially flat surface.

(Central exhaust chamber 540)

As shown in fig. 2 and 3, the concentrated exhaust chamber 540 is located between the injection chamber 510 and the cell communication single chamber 520 in each end-side divided chamber 500. The concentrated exhaust chamber 540 is a space surrounded by the concentrated exhaust sidewall 542, and has a substantially circular shape as viewed in the vertical direction. Specifically, as shown in fig. 4 and 6, a substantially arc-shaped cap concentrated exhaust side wall 342 having a third notch portion 341 formed on the cap filling side wall 312 side is formed on the upper surface of the cap main body 302 so as to protrude upward from the cap main body 302. On the other hand, as shown in fig. 5 and 6, a substantially cylindrical upper cover concentrated exhaust side wall 442 is formed on the lower surface of the upper cover main body 402 so as to protrude downward from the upper cover main body 402 at a position facing the middle cover concentrated exhaust side wall 342. A duct 443 communicating with the discharge port 405 is formed in the upper lid concentrated exhaust sidewall 442. Central exhaust chamber 540 is formed inside lid 14 by joining central exhaust side wall 342 and top concentrated exhaust side wall 442 by thermal fusion bonding to form central exhaust side wall 542 (see fig. 2 and 3). Further, a filter, not shown, is disposed in the concentrated exhaust chamber 540, and the gas G that has entered the inside of the lid concentrated exhaust side wall 342 from the exhaust flow path 530 through the third notch 341 enters the side of the lid concentrated exhaust side wall 442 through the filter and is discharged to the outside of the lead acid battery 100 (lid 14) through the discharge port 405.

(exhaust flow path 530)

As shown in fig. 6, the exhaust flow path 530 communicates with the cell communication unit chamber 520 via the second notch portion 321, and communicates with the discharge port 405. Specifically, in the end-side compartment 500, the exhaust passage 530 directly communicates with the collective exhaust chamber 540, and further communicates with the discharge port 405 via the collective exhaust chamber 540. In the end-side compartment 500, the air discharge flow path 530 extends from the second cutout 321, around the outer periphery of the air discharge side wall 522, between the cell communication single cell 520 and the concentration air discharge chamber 540, around the outer periphery of the injection chamber 510, and to the third cutout 341 of the concentration air discharge chamber 540.

More specifically, as shown in fig. 4 and 6, a connecting wall 352 that connects the middle cap liquid injection side wall 312 and the middle cap concentrated exhaust side wall 342 is formed on the upper surface of the middle cap main body 302 so as to protrude upward from the middle cap main body 302. Thus, the inner lid 300 is formed with an inner lid air vent channel 354 surrounded by the inner lid peripheral wall 304, the inner lid air vent side wall 322, the inner lid partition wall 306, the inner lid liquid injection side wall 312, and the connection wall 352. The bottom surface of the middle lid main body 302 in the middle lid exhaust flow path 354 is flush with the entire length of the middle lid exhaust flow path 354, and is inclined toward the second notch 321. Thus, when the lead-acid battery 100 is in the normal posture, the electrolyte 18 leaking through the exhaust passage 530 can be smoothly returned to the cell communication cells 520 through the bottom surface of the inner lid exhaust passage 374. That is, the middle cover exhaust flow path 354 is continuously connected over the entire length. Further, a plurality of ribs 356 are formed in the middle cap exhaust flow path 354. The plurality of protruding strips 356 trap mist (water vapor) contained in the gas G from the second cut portion 321 toward the third cut portion 341, and condense the mist into water. The plurality of convex strips 356 suppress the electrolyte 18 flowing out from the cell communication cell 520 to the exhaust flow path 530 through the second notch 321 from flowing toward the discharge port 405.

On the other hand, as shown in fig. 5 and 6, a first connecting wall 452 that connects the upper lid partition wall 406 and the upper lid concentrated exhaust side wall 442, a second connecting wall 454 that connects the upper lid partition wall 406 and the upper lid liquid injection side wall 412, and a third connecting wall 456 that connects the upper lid liquid injection side wall 412 and the upper lid concentrated exhaust side wall 442 are formed on the lower surface of the upper lid main body 402 so as to protrude downward from the upper lid main body 402. No cutout portion is formed in each of the first coupling wall 452, the second coupling wall 454, and the third coupling wall 456. Thus, a first upper cover space 460, a second upper cover space 462, and a third upper cover space 464 are formed in the end side partition chamber 500 of the upper cover 400. First lid space 460 is a space surrounded by lid peripheral wall 404, lid exhaust side wall 422, lid concentrated exhaust side wall 442, and connecting wall 452, and is disposed closest to second notch 321. The second upper cover space 462 is a space surrounded by the upper cover partition wall 406, the first connecting wall 452, the second connecting wall 454, and the third connecting wall 456, and is disposed at a position farther from the second cutout 321 than the first upper cover space 460. The third cover space 464 is a space surrounded by the cover peripheral wall 404, the cover partition wall 406, the cover filling side wall 412, the second connecting wall 454, and the third connecting wall 456, and is disposed at a position farther than the second cover space 462 with respect to the second cutout 321. As described above, in the end-side chamber 500, the exhaust gas flow path 530 is continuously connected to the middle lid 300, and is divided into 3

spaces

460, 462, and 464 by the first connecting wall 452, the second connecting wall 454, and the third connecting wall 456 on the upper lid 400 side. In addition, the total volume of the second upper cover space 462 and the third upper cover space 464 (the accommodation volume of the electrolyte 18) is larger than the volume of the upper cover exhaust sidewall 422. In addition, the volume of the first upper cover space 460 is larger than the volume of the second upper cover space 462.

Among the plurality of divided chambers 500, the exhaust flow path 530 communicates with the concentrated exhaust chamber 540 via the other divided chamber 500 in the divided chamber 500 located inside the end side divided chamber 500 in the cell arrangement direction (X-axis direction) (hereinafter referred to as "inside divided chamber 500"). In the inner compartment 500, the exhaust flow path 530 extends from the second notch 321, around the outer periphery of the exhaust sidewall 522, between the cell communication cell 520 and the concentrated exhaust chamber 540, and reaches the first notch 407 formed in the lid partition 406.

More specifically, as shown in fig. 4, the inner lid 300 is formed with an inner lid air vent passage 374 surrounded by the inner lid peripheral wall 304, the inner lid air vent side wall 322, the inner lid partition wall 306, and the inner lid liquid injection side wall 312. The bottom surface of the inner lid main body 302 in the inner lid exhaust passage 374 is flush with the entire length of the inner lid exhaust passage 374, and is inclined toward the second notch 321. That is, the middle cover exhaust passage 374 is continuously connected over the entire length. Thus, when the lead-acid battery 100 is in the normal posture, the electrolyte 18 leaking through the exhaust passage 530 can be smoothly returned to the cell communication cells 520 through the bottom surface of the inner lid exhaust passage 374. Further, a plurality of ribs 356 are formed in the middle cap exhaust passage 374. These convex strips 356 trap mist (water vapor) contained in the gas G from the second cut portion 321 toward the third cut portion 341, and condense the mist into water. The plurality of convex strips 356 suppress the electrolyte 18 flowing out from the cell communication cell 520 to the exhaust flow path 530 through the second notch 321 from flowing toward the first notch 407.

On the other hand, as shown in fig. 5, a fourth connecting wall 472 that connects the opposing upper cap partition walls 406 and a pair of fifth connecting walls 474 that connect the upper cap liquid injection side wall 412 and the upper cap partition wall 406 are formed on the lower surface of the upper cap body 402 so as to protrude downward from the upper cap body 402. No cutout portion is formed in either the fourth coupling wall 472 or the fifth coupling wall 474. Thus, the fourth upper cover space 480, the fifth upper cover space 482, and the sixth upper cover space 484 are formed in the inner compartment 500 of the upper cover 400. The fourth lid space 480 is a space surrounded by the lid peripheral wall 404, the lid partition wall 406, the lid exhaust side wall 422, and the fourth connecting wall 472, and is disposed at a position closest to the second notch 321. The fifth cap space 482 is a space surrounded by the cap partition wall 406, the fourth connecting wall 472, the cap filling side wall 412, and the fifth connecting wall 474, and is disposed at a position farther from the fourth cap space 480 than the second notch 321. The sixth lid space 484 is a space surrounded by the lid peripheral wall 404, the lid partition wall 406, the lid filling side wall 412, and the fifth connecting wall 474, and is disposed at a position farther than the fifth lid space 482 with respect to the second notch 321. As described above, in the inner compartment 500, the exhaust passage 530 is continuously connected to the middle lid 300, and is partitioned into 3 spaces 480, 482, 484 by the fourth connecting wall 472 and the fifth connecting wall 474 on the upper lid 400 side.

A-3. effects of the present embodiment:

when the lead-acid battery 100 is in the inverted posture, the electrolyte 18 in the cell chamber 16 flows into the cell communication cell chamber 520 through the communication holes (the exhaust hole 328 and the return hole 330) formed in the cell communication cell chamber 520, and the water level of the electrolyte 18 in the cell communication cell chamber 520 rises. When the water level of the electrolyte 18 reaches the second notch 321 formed in the cell communication cell 520, the electrolyte 18 may flow out to the outside (the exhaust flow path 530) of the cell communication cell 520 through the second notch 321.

Here, if the end portion 432A of the exhaust cylinder wall 432 is disposed closer to the lid body 402 (the Z-axis positive direction side) than at least a part of the second notch 321 and the distance between the exhaust cylinder wall 432 and the second notch 321 is longer than the distance between the exhaust cylinder wall 432 and the exhaust hole 328 and the return hole 330, the electrolyte 18 is likely to flow out of the cell communication cell 520. That is, in these structures, there is no obstacle that prevents air present in the exhaust flow path 530 from flowing into the cell communication cell 520 through the second notch 321. Therefore, the air present in the exhaust flow path 530 easily enters the cell communication cell 520 through the second notch 321. As a result, the electrolyte 18 easily flows out to the exhaust flow path 530 by so-called gas-liquid replacement, in which air flows into the cell communication single chamber 520 from the exhaust flow path 530 and the electrolyte 18 flows out to the exhaust flow path 530 from the cell communication single chamber 520.

In contrast, in the lead-acid battery 100 of the present embodiment, the cell communication cell 520 includes the exhaust cylinder wall 432, and the exhaust cylinder wall 432 is disposed so as to face the second notch 321 at a position close to the second notch 321. Further, the end portion 432A of the exhaust cylinder wall 432 on the cell chamber 16 side (Z-axis negative direction side) is formed closer to the cell chamber 16 side than the second notch portion 321. Therefore, the air present in the exhaust flow path 530 is less likely to enter the cell communication unit cell 520 through the second notch 321, and gas-liquid replacement inside and outside the cell communication unit cell 520 can be suppressed. Thus, according to the present embodiment, it is possible to suppress the electrolyte 18 from flowing out to the exhaust passage 530 and further to the outside of the case 10 when the lead-acid battery 100 is in the inverted posture. Next, the operation and effects according to the present embodiment will be described in more detail.

Fig. 10 is an explanatory diagram showing a change in the water level of the electrolyte 18 in the cell communication unit 520 when the lead storage battery 100 is in the inverted posture. The XZ cross-sectional structure of the cap 14 shown in fig. 10 is a structure in which the XZ cross-sectional structure of the cap 14 shown in fig. 7 is turned upside down. As shown in fig. 10, when the lead-acid battery 100 is in the inverted posture, the electrolyte 18 in the cell chamber 16 flows into the exhaust cylinder wall 432 through the exhaust hole 328. Then, when the space surrounded by the exhaust cylinder wall 432 is filled with the electrolyte 18 (see fig. 10 a), the electrolyte 18 in the exhaust cylinder wall 432 overflows to the outside of the exhaust cylinder wall 432 in the cell communication single chamber 520 (the outside of the exhaust cylinder wall 432 in the upper lid main body 402). When the water level of the electrolyte 18 outside the gas discharge tube wall 432 in the cell communication cell 520 reaches the lower end of the second notch 321, the electrolyte 18 starts to flow out from the cell communication cell 520 to the gas discharge flow path 530 through the second notch 321. When the water level of the electrolyte 18 outside the exhaust cylindrical wall 432 in the cell communication single chamber 520 becomes equal to the water level of the electrolyte in the exhaust cylindrical wall 432 (see fig. 10B), if both the inside and the outside of the exhaust cylindrical wall 432 are not filled with the electrolyte 18, the water level of the electrolyte 18 does not rise, and therefore the rising speed of the water level of the electrolyte 18 in the cell communication single chamber 520 becomes slow.

Here, assuming that the distal end portion 432A of the exhaust cylinder wall 432 is formed at a position closer to the upper cover body 402 side (the lower side in fig. 10 (the positive direction of the Z axis)) than at least a part of the second notch portion 321, a large amount of the electrolyte 18 flows out from the cell communication cell 520 to the exhaust flow path 530. That is, in such a configuration, during a low water level speed period in which the rising speed of the water level of the electrolyte 18 is slow, a continuous space continuously connected from the second notch 321 to the return hole 330 exists for a long time in the cell communication single chamber 520, so that gas-liquid replacement inside and outside the cell communication single chamber 520 is promoted via the continuous space, and a large amount of the electrolyte 18 flows out from the cell communication single chamber 520 to the exhaust flow path 530.

In contrast, in the lead-acid battery 100 of the present embodiment, the distal end portion 432A of the exhaust casing wall 432 is formed at a position closer to the cell compartment 16 side (upper side (Z-axis negative direction side) in fig. 10) than the second notch portion 321. Therefore, when the water levels of the electrolyte solution 18 inside and outside the exhaust casing wall 432 become equal, the second notch 321 is already closed by the electrolyte solution 18, and the continuous space does not exist, so that the air existing in the exhaust flow path 530 is less likely to enter the cell communication cell 520 through the second notch 321. Thus, during the low water level speed period, gas-liquid replacement inside and outside the cell communication cells 520 is less likely to occur, and outflow of the electrolyte 18 from the cell communication cells 520 to the exhaust flow path 530 can be suppressed. That is, according to the lead-acid battery 100 of the present embodiment, the outflow of the electrolyte 18 from the cell communication cells 520 to the exhaust flow path 530 can be more effectively suppressed when the lead-acid battery 100 is in the inverted posture.

In addition, in the structure in which the vent hole 328 and the return hole 330 positioned closer to the cell chamber 16 side (the Z-axis negative direction side) than the vent hole 328 are formed in the cell communication cell chamber 520 as in the lead-acid battery 100 of the present embodiment, when the lead-acid battery 100 is in the inverted posture, the water level of the electrolyte 18 in the cell communication cell chamber 520 reaches the vent hole 328 before the return hole 330. As a result, the exhaust hole 328 is closed by the electrolyte 18, and the return hole 330 is opened. Here, if the second notch 321 is formed closer to the return hole 330 than the exhaust hole 328, a large amount of the electrolyte solution 18 flows out from the cell communication cell 520 to the exhaust flow path 530. That is, even if the water level of the electrolyte 18 in the cell communication single chamber 520 reaches the exhaust hole 328, a continuous space continuously connecting from the second notch 321 to the return hole 330 exists in the cell communication single chamber 520, and gas-liquid replacement inside and outside the cell communication single chamber 520 is promoted via the continuous space, so that a large amount of the electrolyte 18 flows out from the cell communication single chamber 520 to the exhaust flow path 530.

In contrast, in the lead acid battery 100 of the present embodiment, the second notch 321 is formed closer to the air outlet hole 328 than the return hole 330. Therefore, when the lead-acid battery 100 is in the inverted posture and the water level of the electrolyte 18 in the cell communication single chamber 520 reaches the air outlet 328, the electrolyte 18 stored in the cell communication single chamber 520 is present between the second notch 321 and the return hole 330 in the cell communication single chamber 520. That is, a continuous space continuously connecting from the second notch 321 to the return hole 330 is not formed in the cell communication single chamber 520. Therefore, gas-liquid replacement inside and outside the cell communication single chamber 520 can be suppressed. Thus, according to the lead-acid battery 100 of the present embodiment, the outflow of the electrolyte 18 from the cell communication cells 520 to the exhaust flow path 530 can be more effectively suppressed when the lead-acid battery 100 is in the inverted posture.

In the lead-acid battery 100 of the present embodiment, at least a part of the surfaces of the exhaust casing wall 432 and the exhaust side wall 522 facing each other, which form the internal flow path Q communicating with the second notch 321 and located on the cell compartment 16 side (the Z-axis negative direction side) of the second notch 321, has the uneven portion T. As a result, as shown in fig. 10 (C), when the lead-acid battery 100 is in the inverted posture, the electrolyte 18 in the cell chamber 16 flows into the cell communication cell 520, and the second notch 321 is closed by the electrolyte 18, the air entering the cell communication cell 520 from the exhaust passage 530 is prevented from moving to the return hole 330 by the concave-convex portion T. This makes it difficult to cause gas-liquid replacement inside and outside the cell communication unit chamber 520, and can suppress the outflow of the electrolyte solution 18 from the cell communication unit chamber 520 to the exhaust flow path 530.

In the lead-acid battery 100 of the present embodiment, the surfaces of the partitions (the first partition 324 and the second partition 326) in which the second notch 321 is formed on the upper cover body 402 side are substantially flat surfaces, and the surfaces of the flow path walls (at least a part of the opposed surfaces of the exhaust cylinder wall 432 and the exhaust side wall 522 opposed to each other) have the uneven portions T. Thus, when the lead-acid battery 100 is returned from the inverted posture to the normal posture, the electrolyte 18 in the cell communication cell chamber 520 can be smoothly guided to the return hole 330 via the partition wall and returned to the cell chamber 16, as compared with the case where the concave-convex portion is formed in the partition wall.

In the lead-acid battery 100 of the present embodiment, a plurality of connecting walls (452, 454, 472, 474) are formed at the portion of the upper cover body 402 that constitutes the exhaust passage 530. Each connecting wall projects from the upper cover body 402 toward the cell compartment 16 side and extends continuously over the entire width of the exhaust flow path 530 in the direction intersecting the exhaust flow path 530. Thus, for example, even when the lead-acid battery 100 is in an inverted posture, the electrolyte 18 in the cell chamber 16 flows into the exhaust passage 530 through the cell communication single chamber 520, and the electrolyte 18 is first left between the cell communication single chamber 520 and the respective connection walls. Then, when the electrolyte 18 flows out beyond the connecting walls, it flows into the side of the discharge port 405 with respect to the connecting walls. That is, according to the lead acid battery 100 of the present embodiment, the inflow of the electrolytic solution 18 to the discharge port 405 side of the lid 14 can be suppressed as compared with the structure in which the vent flow path 530 is not formed with the connecting wall.

The total volume of the second and

third cover spaces

462 and 464 is larger than the volume of the cover exhaust sidewall 422. Thus, the electrolyte 18 flowing from the cell communication cell 520 into the exhaust passage 530 hardly reaches the third cover space 464 closest to the discharge port 405 formed in the cover 14, and therefore the electrolyte 18 can be prevented from leaking to the outside of the lead acid battery 100 through the discharge port 405.

In the lead-acid battery 100 of the present embodiment, the volume of the first lid space 460 is larger than the volume of the second lid space 462. Thus, in comparison with a configuration in which the volume of the first lid space 460 is smaller than the volume of the second lid space 462, the electrolyte 18 flowing out of the cell communication unit chamber 520 hardly crosses the partition wall closest to the cell communication unit chamber 520, and the approach to the discharge port side of the lid can be suppressed.

B. Modification example:

the technique disclosed in the present specification is not limited to the above-described embodiments, and can be modified in various ways without departing from the scope of the invention.

In the above-described embodiment, the exhaust duct wall 432 formed so as to protrude from the opposing wall (the upper cover main body 402) constituting the cell communication cell 520 is exemplified as the inner wall, but a wall separated from the opposing wall, a wall having a shape other than a cylindrical shape such as a flat plate shape, or the like may be used as long as the inner wall faces the second cutout portion 321.

In the above embodiment, the lid 14 may not include the communication cylinder portion 332. In the above embodiment, the lid 14 may be configured such that the second notch 321 is formed closer to the return hole 330 than the air vent 328. In the above embodiment, the backflow hole 330 may not be formed in the cell communication single chamber 520.

In the above embodiment, the bottom surface of the inner lid exhaust passage 374 of the inner lid main body 302 may be provided with a partition wall on the same plane throughout the entire length of the inner lid exhaust passage 374, or may not be inclined toward the second notch 321.

In the above embodiment, the concave-convex portion T may be formed on both surfaces of the opposed surfaces of the exhaust cylinder wall 432 and the exhaust side wall 522, or the concave-convex portion T may be formed only on one surface. Further, the concave-convex portion T may be formed on the upper surface of the middle cap body 302. In addition, the concave-convex portion T may be formed only on 1 or 2 of the remaining 3 outer side surfaces of the exhaust funnel wall 432. The concave-convex portion T may not be formed on the surface of the exhaust cylinder wall 432 facing the exhaust side wall 522. The concave-convex portion T is not limited to extending in a predetermined direction, and may be formed of a hemispherical or columnar convex portion, for example. In addition, when the lead-acid battery 100 is in the inverted posture and the second notch 321 is closed by the electrolyte 18, as another configuration for suppressing the movement of the air that enters the cell communication cell 520 from the air discharge flow path 530 to the return hole 330, the surface roughness of at least a part of the facing surfaces of the exhaust cylinder wall 432 and the exhaust side wall 522 may be made larger than the surface roughness of the lower surface of the upper cover main body 402.

In the above embodiment, the portion of the upper cover main body 402 constituting the exhaust flow path 530 may be divided into 2, or may be divided into 4 or more. In addition, the volume of the first upper cover space 460 may be smaller than the volume of the second upper cover space 462. The total volume of the second cover space 462 and the third cover space 464 may be equal to or less than the volume of the cover exhaust sidewall 422.

Description of the reference numerals

The storage battery comprises a housing 10 …, a 12 … electrolytic cell, a 14 … cover, a 16 … cell chamber, an 18 … electrolyte, a 20 … electrode group, a 30 … positive electrode side terminal portion, a 32 … positive electrode side post sleeve, a 34 … positive post, a 40 … negative electrode side terminal portion, a 42 … negative electrode side post sleeve, a 44 … negative post, a 52 … positive electrode side bus bar, a 54 … negative electrode side row, a 56 … connecting part, a 58 … partition wall, a 100 … lead storage battery, a 210 … positive electrode plate, a 212 positive electrode collector, a 214 … positive electrode ear, a 216 … positive electrode active substance, a 220 negative electrode plate, a 222 … negative electrode ear, a 226 … negative electrode active substance, a 230 … separator, a 300 … intermediate cover, a 302 … intermediate cover body, a 304 … intermediate cover peripheral wall 306, a … intermediate cover 36306, a … intermediate cover 36311, a 36311, a 36311 … intermediate cover, a … intermediate cover …, a … intermediate cover, a … intermediate cover … intermediate space …, a … intermediate space 36320, a … intermediate space 36320, a … intermediate space 36320 intermediate space … intermediate space 36320 intermediate space … intermediate space 36320, a … intermediate cover … intermediate space 36320 exhaust cover 36320 intermediate space 36320, a … intermediate cover … intermediate space … intermediate cover … intermediate space 36320 intermediate space ….

Claims

1. A lead-acid battery is provided with:

an electrolytic cell having an opening on one side in a first direction and having a housing chamber formed therein, the housing chamber communicating with the opening;

a positive electrode and a negative electrode accommodated in the accommodation chamber of the electrolytic cell; and

a cover configured to close the opening of the electrolytic cell, the cover having a discharge port formed on an outer surface thereof,

a communication chamber is formed inside the cover, the communication chamber being surrounded by a partition wall between the communication chamber and the housing chamber, an opposing wall opposing the partition wall to each other in the first direction, and a side wall connecting the partition wall and the opposing wall,

a communication hole communicating with the housing chamber is formed in the partition wall,

a vent hole communicating with the discharge port of the lid is formed in the side wall,

the communication chamber is provided with an inner wall disposed opposite to the vent hole,

a first distance between the inner wall and the vent hole in the side wall is shorter than a second distance between the inner wall and the communication hole,

the terminal portion of the inner wall on the other side in the first direction is formed closer to the other side in the first direction than the vent hole.

2. The lead-acid battery according to claim 1,

the inner wall is a cylindrical exhaust cylinder wall protruding from the opposing wall toward the communication hole.

3. The lead-acid battery according to claim 2,

the communication hole includes an exhaust hole communicating with the housing chamber, and a return hole located on the other side in the first direction than the exhaust hole and communicating with the housing chamber,

the vent hole is formed in the communication chamber at a position closer to the exhaust hole than the return hole.